1. Field of the Invention
The present invention relates to a press-contact pogo pin connector used mainly as a battery connector for small electronic devices such as mobile phones.
2. Description of the Related Art
Press-contact connectors with pogo pins are conventionally used as battery connectors for mobile phones.
As show in FIG. 11, in conventional pogo pins used for such press-contact connectors, a pin 3 urged in its protruding direction by a coil spring 2 is movably installed inside a metal-made closed-end cylinder 1 with the end of a press-contact pin 3a of the pin 3 protruding from the end of the cylinder 1. The press-contact pin 3a is to be brought into press-contact with a contact terminal of a battery by the urging force of the coil spring 2 in the protruding direction.
A bias cut surface 4 inclined with respect to the axial direction is formed on the cylinder-side inner end surface of the pin 3. The coil spring 2 pushes the bias cut surface 4, and a force component perpendicular to the pushing direction is thereby generated. This force component causes the circumferential surface of the pin 3 to be in press-contact with the inner surface of the cylinder 1 at all times, and this allows electric current to flow from the pin 3 through the cylinder 1.
In a press-contact connector with such pogo pins, the cylinder and the pins are produced using various machining devices such as a lathe, milling machine, and press. Therefore, the manufacturing cost is high, and a reduction in size is limited due to mechanical machining. Another problem is that, since the cylinder is installed inside a molded housing, the overall height of the connector cannot be small. Still another problem is that, since the connector is configured such that the pin 3 can radially move within the cylinder 1, an instantaneous interruption can easily occur when an external shock is applied.
To reduce the machining cost and to improve the resistance to instantaneous interruption, a press-contact connector shown in FIG. 12 has been developed (for example, WO2005/112200). In this connector, a pin 3 and a cylinder 1 that receives the pin 3 are produced by stamping and bending a metal plate, and the electrical continuity between the cylinder 1 and the pin 3 is ensured by allowing an elastic contact member 5 projecting along the inner surface of the cylinder 1 to come in press-contact with the external circumferential surface of the pin 3 at all times.
In the connector having a cylinder and a pin formed by bending a plate as shown in FIG. 12, the machining cost is reduced, and the resistance to external shock is improved. However, both the cylinder used as an outer cylinder and the pin used as an inner cylinder are produced by machining metal members and are incorporated in a molded housing. Therefore, the problem with this press-contact connector is that its height does not satisfactorily meet the low profile requirement when the connector is mounted in a direction parallel to a substrate.